Oil Pump with Improved Structure

ABSTRACT

An oil pump with improved structure comprises a motor casing, a motor cap, and an oil pump. The motor cap comprises a through hole, and is used for the enclosure of a motor in cooperation with the motor casing. The interior of the motor is assemblingly provided with a rotating shaft passing at one end thereof through the through hole of the motor cap and an oil pump joint. The oil pump comprises the oil pump joint, a cap body, and a rotor, the oil pump joint is projectingly provided on and integratedly formed with the motor cap. The rotor of the oil pump is assemblingly provided on the rotating shaft of the motor. In this case, neither the need for the connection or additional manufacture and assembly of a rotating shaft of the oil pump, nor the problem resulted from the interconnection may occur. Moreover, the concentricity may be assured, and the cost may be reduced significantly as well.

FIELD OF THE INVENTION

The present invention is related to a technical field of an oil pump structure, particularly to an oil pump with improved structure.

BACKGROUND

Referring to a conventional “semi-rotary fluid pump” structure, the technical content thereof is characterized by:

a body having a bore, the body being provided therein with a receptacle in communication with the oil inlet and outlet thereof, the receptacle being allowed to communicate with the exterior and eccentrically positioned with respect to the bore;

an outer rotor, coaxially positioned with respect to the receptacle and movably provided in the receptacle, in which there is provided with a through hole, having a specific geometric form, provided coaxially with respect to the bore of the body;

a shaft rod passing through the bore of the body;

an inner rotor, supplying oil by compression in cooperation with the outer rotor during rotation, provided coaxially with the shaft rod passing therethrough and accommodated in the through hole, the inner rotor being relatively positioned with a relative position relation between the interior thereof and the shaft rod in a rotary direction;

at least one bearing provided for the shaft rod passing therethrough, in which the at least one bearing seated on the shaft rod is positioned on at least one side, with respect to two sides of the receptacle, of the body; and

a cap body coveringly provided at one end of the body where the receptacle is provided.

However, there still exist in the above conventional semi-rotary fluid pump several disadvantages as follows.

Referring to FIG. 4, there is shown a conventional oil pump, in which a shaft rod 2 must be machined to form two assembly planes 21, 22, while the end surface of a shaft rod 11 of a motor 1 is also required to form a joining groove 111 therein. It is also necessary for the joining groove 111 to be provided with two corresponding assembly planes 112, 113. However, the machining of the groove in the shaft rod 11 is not easy, and the concentricity is also not accurate, which may cause the shaft rod 2 of the oil pump to be apt to break. Heat treatment, if required, is also not simple. The manufacturing cost is higher as well, and the cost for machining such connecting structure is also high. Low transmission efficiency with a tendency to breakage of the shaft rod 2 may occur due to poor concentricity after connection with no recalibration allowed. These are advantages.

Referring to FIG. 5, there is shown a coupler 3 having been developed for eliminating the disadvantages of the pump described above, in which two shaft bases 31, 32 are used to connect with the shaft rod of the motor and the shaft rod of the pump, respectively. On opposing surfaces of the two shaft bases 31, 32, there are provided with notches 311, 321, and projection portions 312, 322, respectively. Moreover, between the two shaft bases 31, 32, there is provided with an elastic member 33, a projection portion 331 of which is just inserted between the projection portions 312 and 322 of the two shaft bases 31, 32. In this connection, the shaft rod may be not apt to break due to the fact that poor concentricity between shafts may be compensated by the elastic member 33. Nevertheless, there is still a need to additionally provide the coupler 3, which is bulky as well as wasting space in such a way it is impossible to install the coupler 3 if there is no enough space between the motor and the pump. Additionally, the shaft rod must be elongated, and it is not economic because of high cost of the coupler 3 and the interconnection. Furthermore, a joining operation is still required. Thus, further improvement is truly necessary.

SUMMARY OF THE INVENTION

Technical problems to be solved will be described as follows. For a conventional oil pump, a shaft rod thereof must be machined to form two assembly planes, while the end surface of a shaft rod of a motor is also required to form a joining groove therein. The machining of the groove in this shaft rod is not easy, and the concentricity is also not accurate, which may cause the shaft rod of the oil pump to be apt to break. Heat treatment, if required, is also not simple. The manufacturing cost is higher as well, and the cost for machining such connecting structure is also high. For eliminating the disadvantages of the pump described above, a coupler has been developed, in which two shaft bases are used to connect with the shaft rod of the motor and the shaft rod of the pump, respectively. On opposing surfaces of the two shaft bases, there are provided with notches, and projection portions, respectively. Moreover, between the two shaft bases, there is provided with an elastic member. Nevertheless, there is still a need to additionally provide the coupler, which is bulky as well as wasting space in such a way it is impossible to install the coupler if there is no enough space between the motor and the pump. Additionally, the shaft rod must be elongated, and it is not economic because of high cost of the coupler and the interconnection. Furthermore, a joining operation is still required.

Technical features of the solution will be described as follows. There is provided an oil pump with improved structure comprising a motor casing, a motor cap, and an oil pump, the motor cap comprising a through hole, fixedly provided on one side of the motor casing, and used for the enclosure of a motor in cooperation with the motor casing. The interior of the motor is assembling provided with a rotating shaft passing at one end thereof through the through hole of the motor cap and an oil pump joint. The oil pump comprises the oil pump joint, a cap body, and a rotor, the oil pump joint is projectingly provided on and integratedly formed with the motor cap. The rotor of the oil pump is assembling provided on the rotating shaft of the motor, while the oil pump joint is sealing covered by the cap body. In this case, neither the need for the connection or additional manufacture and assembly of a rotating shaft of the oil pump, nor the problem resulted from the interconnection may occur. Moreover, the concentricity may be assured, and the cost may be reduced significantly as well.

In the above, the rotor comprises an inner rotor and an outer rotor, the inner rotor being assembling provided on the rotating shaft, while assembling provided inside the outer rotor. By means of cooperative coupling between the rotating shaft and the inner rotor, the former may be further cooperatively coupled with the outer rotor.

In this connection, the oil pump joint and the motor cap are formed intergratedly by casting.

In comparison to the prior art, the present invention provides effects as follows:

-   -   1. For the conventional oil pump, the shaft rod thereof must be         machined to form the two assembly planes, while the end surface         of the shaft rod of the motor is also required to form the         joining groove therein. The machining of the groove in this         shaft rod is not easy, the concentricity is not accurate, and         the assembly process is difficult. Conversely, the shaft rod of         the motor in the present invention is extended to the oil pump         in such a way that no need for a connecting rod and also no         problem in assembly occur.     -   2. In the conventional oil pump, the coupler is used to assemble         the two shaft rods. However, the coupler is costly, and is bulky         such that enough space is required for installation. Conversely,         in the present invention, there is no need for the coupler,         because the shaft rod of the motor is extended to the oil pump         directly, thus eliminating the problem in assembly and assuring         precise concentricity, so as to raise precision effectively.         Moreover, several effects, such as avoiding the vibration         generated during operation, and prolonged service life, for         example, may be obtained accordingly.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective exploded diagram of an oil pump according to one embodiment of the present invention.

FIG. 2 is a perspective diagram of the oil pump according to the embodiment of the present invention.

FIG. 3 is an assembly section view of the oil pump according to the embodiment of the present invention.

FIG. 4 is a perspective exploded diagram of a conventional oil pump.

FIG. 5 is a perspective exploded diagram of another conventional oil pump.

DETAILED DESCRIPTION

Referring FIGS. 1 to 3, there is shown an oil pump with improved structure provided by the present invention, which comprises a motor casing 42, a motor cap 43, and an oil pump 50, in which the motor cap 43 comprises a through hole 431, the motor cap 43 being fixedly provided on one side of the motor casing 42, and being used for the enclosure of a motor 40 in cooperation with the motor casing 42. The interior of the motor 40 is assemblingly provided with a rotating shaft 41 passing at one end thereof through the through hole 431 of the motor cap 43 and an oil pump joint 51. The oil pump 50 comprises the oil pump joint 51, a cap body 54, and a rotor, the oil pump joint 51 being projectingly provided on and integratedly formed with the motor cap 43. The rotor of the oil pump 50 is assemblingly provided on the rotating shaft 41 of the motor 40, while the oil pump joint 51 is sealingly covered by the cap body 54. In this case, neither the need for the connection or additional manufacture and assembly of a rotating shaft of the oil pump, nor the problem resulted from the interconnection may occur. Moreover, the concentricity may be assured, and the cost may be reduced significantly as well.

In the above, the rotor comprises an inner rotor 52 and an outer rotor 53, the inner rotor 52 being assemblingly provided on the rotating shaft 41, while assemblingly provided inside the outer rotor 53. By means of cooperative coupling between the rotating shaft 41 and the inner rotor 52, the former may be further cooperatively coupled with the outer rotor 53.

In this connection, the oil pump joint 51 and the motor cap 43 are formed intergratedly by casting.

For the oil pump with improved structure of the present invention, the motor cap 43 and the oil pump joint 51 are formed integratedly, and the rotating shaft 41 of the motor 40 is used as the rotating shaft of the oil pump 50 as well. Thus, the features of simple construction, fewer parts, and quite easy assembly are provided, together with assurance of concentricity, by the present invention, without either the problem of so-called poor concentricity resulted from the assembly of two shafts, or the problem arising from the installation of the coupler.

To sum up, firstly, for the conventional oil pump, the shaft rod thereof must be machined to form the two assembly planes, while the end surface of the shaft rod of the motor is also required to form the joining groove therein. The machining of the groove in this shaft rod is not easy, the concentricity is not accurate, and the assembly process is difficult. Conversely, the shaft rod of the motor in the present invention may extend to the oil pump in such a way that no need for a connecting rod and also no problem in assembly occur. Additionally, in the prior art, the coupler is used to assemble the two shaft rods. However, the coupler is costly, and is bulky such that enough space is required for installation. Conversely, in the present invention, there is no need for the coupler, because the shaft rod of the motor may extend to the oil pump directly, thus eliminating the problem in assembly and assuring precise concentricity, so as to raise precision effectively. Moreover, several effects, such as avoiding the vibration generated during operation, and prolonged service life, for example, may be obtained accordingly. 

1. An oil pump with improved structure, comprising: a motor casing; a motor cap comprising a through hole, fixedly provided on one side of said motor casing, and used for the enclosure of a motor in cooperation with said motor casing, the interior of said motor being assemblingly provided with a rotating shaft passing at one end thereof through said through hole of said motor cap and an oil pump joint; and an oil pump comprising said oil pump joint, a cap body, and a rotor, said oil pump joint being projectingly provided on and integratedly formed with said motor cap, said rotor of said oil pump being assemblingly provided on said rotating shaft of said motor, while said oil pump joint being sealingly covered by said cap body.
 2. The oil pump with improved structure according to claim 1, wherein said rotor comprises an inner rotor and an outer rotor, said inner rotor being assemblingly provided on said rotating shaft, while assemblingly provided inside said outer rotor, said rotating shaft being further cooperatively coupled with said outer rotor by means of cooperative coupling between itself and said inner rotor.
 3. The oil pump with improved structure according to claim 1, wherein said oil pump joint and said motor cap are formed intergratedly by casting. 